The technical field concerned by the present invention is more particularly that of means for the mechanical testing of parts in full scale. These are tests during which parts in actual size are submitted to mechanical loads for which they have been dimensioned, either for checking that they really are capable of supporting such loads whether in the initial state, after ageing or after damage, or for certifying the same with respect to standards or regulations, or for determining the fatigue behavior thereof. Such tests are more particularly carried out for the certification of airplanes.
The invention more particularly relates to a testing means intended to stress curved panels, or more generally sectors of structures of revolution, such as fuselage elements or wing panels.
The tests to be carried out are very complex tests since they must simulate all the loads which an actual part is submitted to. This means that, in particular for a panel, transversal and axial stresses in traction and/or in compression, radial stresses (internal pressure in the plane), torsion and/or shearing, all in a combination must be provided while complying with the geometry of the structure of which the panel is an element.
Such tests can possibly be carried out under variable and controlled temperature and hygrometry conditions which are representative for example of the flight of an airplane, with temperatures from −70° C. up to +100° C., and hygrometry varying from 0 to 100% or under cryogenic or very hot conditions in the case of a space launcher.
The document US 2006/0101921 in the name of BOEING summarizes the problems to be faced for such simulations, i.e. radial simulations, shearing simulations combined with axial and transversal loads, radial stress and the necessity of carrying out numerical calculations and a complex piloting for simulating the behavior of panels at the interfaces thereof.
This document provides to provide all the stresses simultaneously under variable and controlled conditions and therefore describes various complex devices including the traction/compression system for the axial stress, a hydraulic displacement system of such traction system for applying shearing, membranes for enabling pressurization, a device including push links actuated by jacks driven by a computer to provide transversal loads.
This document describes a mechanically very complex device which requires sophisticated calculations to define the various stresses resulting from the various loads, more particularly to know the share of the transversal load.
The documents FR 2 889 310 and FR 2 889 311 provide testing segments of the whole fuselage to avoid the problems resulting from the tests on the panels. This makes it possible to use means which are easier to design and implement since when testing panels, the difficulty lies in the limit conditions and there are fewer limit conditions in a segment of the fuselage than in a panel of the fuselage. More particularly, the transversal loading problem no longer exists, and the radial loading can simply be simulated by the internal pressurization of the fuselage.
Such solutions which are applied to entire structures require gigantic and complex testing means which are totally out of proportion with respect to the tests to be carried out.